A new ONS report makes for us a point that I've been regularly presenting to you over the past couple of years. Yes, there most certainly is variation in age at death across the country. And yes, those in more deprived areas do indeed tend to die younger than those in more affluent ones. But this isn't, and isn't from somewhere between not very much and a lot, because living in a deprived area kills you. Rather, it's because people migrate in and out of deprived and affluent areas and those doing the migrating tend to have different health prospects:

One factor that has received less attention is the selective migration of healthy individuals from poorer health areas into better health areas or vice-versa. This type of migration has been shown to play a significant role in increasing or decreasing location-specific illness and mortality rates, which then consequently impact on life expectancy figures. Norman, Boyle and Rees (2005) demonstrated that the largest absolute flow within England and Wales between 1971 and 1991 was of relatively healthy people moving from more deprived into less deprived areas. The impact of this migration was to raise ill-health and mortality rates where these people originated from and lower them in the destination areas. The authors also noted that the benefit to less deprived areas was reinforced by a significant group of people in poor health who moved from less to more deprived locations.

This also speaks to the error that is made about health inequality in the UK. Marmot, and thus the system itself, seems to think that it is economic inequality that determines health inequality. Thus, reduce the economic and you'll reduce the health inequality. But as above, we can see that at least sometimes the causation is the other way. People with bad health have bad economic outcomes: that's why they're moving to more deprived, also known as cheaper, areas.

This is that old difference between correlation and causation again. There is undoubtedly a correlation between income in an area and health and lifespan. It's been politically convenient for campaigners to insist that the causation is that the income differences cause the health and lifespan differences. And I've no doubt whatsoever that that is a part of it: but we've also got that reverse causation as well. That the initial health, and thus lifespan, inequalities are part of the cause of the economics ones. Which means, of course, that equalising the economic outcomes will not equalise the health or lifespan ones. And thus we can and should shout at those campaigners who insist that it will.